This document summarizes estimates of change in mature individuals over time for Pacific salmon Designatable Units (DUs) and associated probable COSEWIC status designations. These estimates can then be used to help COSEWIC’s Marine Fishes sub-committee identify high priority DUs for formally assessment. See these links for information on Data sources, the data itself, and code to reproduce this document. These materials are solely intended to support the Marine Fishes sub-committee of COSEWIC, and may not be appropriate for other applications. Data Was compiled by Eric Hertz and colleagues at the Pacific Salmon Commission and documented in this GitHub repository.
Some general questions to consider in the prioritization process.
Have DUs been formally defined by COSEWIC? Chinook, sockeye, and coho salmon DUs have been defined (reports available here), formal pink and chum DU identification is in progress. If yes then proceed.
Is information on mature individuals over time available at the DU scale? If yes then proceed.
Has DU been previously assessed by COSEWIC? If yes then consider a re-assessment, otherwise proceed except for DUs that have already been approved for a status assessment.
What is the DUs probable designation based on percentage change in mature individuals over past three generations? If special concern, threatened or endangered then proceed.
Are there spatial considerations? Are there commonalities in threats, designations, and/or data landscape at a regional scale that suggest a group of DUs should be bundled together?
Figure 1. Status of all DUs. For DUs that have been
previously assessed by COSEWIC the official status is shown, otherwise
probable status is inferred based on percent change in mature individual
abundance over the most recent three generations of data.
Figure 2. Probable status of unassessed, but formally
defined, Pacific salmon DUs (excluding those previously assessed by
COSEWIC or recommended for status assessment) based on rate of change in
mature individuals over most recent three generations.
Plots of reconstructed number of mature individuals (spawners) over time for each DU, by region and species. Show are raw estimates with trend over the most recent three generations (red line) or entire time-series (black dashed line). Trends are estimated on spawner abundance in log(e) space.